AMKOR TECHNOLOGY, INC.

1. Interim Financial Statements

Basis of Presentation. The Consolidated Financial Statements and related disclosures as of September 30, 2026, and for the three and nine months ended September 30, 2026 and 2025, contained in this Form 10-Q (the “Consolidated Financial Statements”) are unaudited pursuant to the rules and regulations of the SEC. The December 31, 2025 Consolidated Balance Sheet data contained in this Form 10-Q was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America (“U.S. GAAP”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to SEC rules and regulations. In our opinion, the Consolidated Financial Statements include all adjustments (consisting only of normal recurring adjustments) necessary for the fair statement of the results for the interim periods and should be read in conjunction with the financial statements included in the 2025 Form 10-K. The results of operations for the three and nine months ended September 30, 2026 are not necessarily indicative of the results to be expected for the full year ending December 31, 2026. Unless the context otherwise requires, all references to “Amkor,” “we,” “us” or “our” are to Amkor Technology, Inc. and its wholly and majority-owned subsidiaries. Certain prior year amounts have been recast to conform to current year presentation.

Use of Estimates. The Consolidated Financial Statements have been prepared in conformity with U.S. GAAP, using management’s best estimates and judgments where appropriate. These estimates and judgments affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. The estimates and judgments will also affect the reported amounts for certain revenues and expenses during the reporting period. Actual results could differ materially from these estimates and judgments as a result of, for example, any worsening of the global business and economic environment.

Restricted Cash. Restricted cash mainly consists of collateral to fulfill construction requirements and funds to be used for labor costs.

Leases. Total long-term finance lease liabilities as of September 30, 2026 and December 31, 2025 were $117.7 million and $105.0 million, respectively.

Goodwill. The balance of goodwill in the Consolidated Balance Sheets contained in this Form 10-Q reflects adjustments for foreign currency translation.

Unbilled Receivables. Total unbilled receivables as of September 30, 2026 and December 31, 2025 were $329.9 million and $294.1 million, respectively.

Contract Liabilities. Contract liabilities were $547.6 million and $390.8 million as of September 30, 2026 and December 31, 2025, respectively. As of September 30, 2026 and December 31, 2025, the short-term portions of the liabilities were $127.5 million and $69.6 million, respectively. Of the remaining contract liability balance as of September 30, 2026, $406.3 million is expected to be recognized in revenue over the next 1-5 years, and $13.9 million over the next 5-10 years. Revenue recognized during the nine months ended September 30, 2026 and 2025 that was included in the contract liabilities balance at the beginning of the period was $46.3 million and $48.7 million, respectively. As of September 30, 2026, $200.0 million of standby letters of credit were issued and outstanding related to customer advance payments received.

Grant Accounting. From time to time, we may receive grants from governmental agencies. We recognize grants in our financial statements when there is reasonable assurance that we will comply with conditions attached to the grants and the grants will be received. Investment tax credits and grants receivable recorded reduce the carrying amounts of the qualifying property, plant and equipment in our Consolidated Balance Sheets.

In July 2026, certain of our subsidiaries entered into a Foreign Direct Investment Cash Support Agreement with governmental authorities in the Republic of Korea pursuant to applicable foreign investment promotion laws. The agreement provides for potential cash grants of up to approximately ₩150 billion (approximately $110 million), subject to the subsidiaries’ achievement of specified investment, employment and other performance conditions over a multi‑year period. Certain real property associated with the investment is pledged as collateral to secure potential repayment under the agreement. As of September 30, 2026, ₩15 billion (approximately $11 million) has been received

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The following table presents investment tax credits and grants receivable as of September 30, 2026 and December 31, 2025:

Recently Issued Standards. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses(“ASU 2024-03”), which was subsequently amended and clarified. ASU 2024-03 requires disaggregation of key expense categories such as inventory purchases, employee compensation, depreciation and intangible asset amortization in the financial statements. ASU 2024-03 is effective for annual reporting periods beginning after December 15, 2026, and interim periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. Adoption of this ASU should be applied either prospectively after the effective date or retrospectively to any or all periods presented in the financial statements. We are currently evaluating the impact of this new standard on our financial statements, which is expected to result in enhanced disclosures.

In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40) (“ASU 2025-06”). ASU 2025-06 removes all references to project stages throughout ASC 350-40 and clarifies the applicable threshold to begin capitalizing costs. ASU 2025-06 is effective for annual reporting periods beginning after December 15, 2027, and interim periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period. Adoption of this ASU should be applied using a prospective transition approach, a modified transition approach based on project status or a retrospective transition approach. We are currently evaluating the impact of this new standard on our financial statements and disclosures.

In December 2025, the FASB issued ASU 2025-10, Government Grants (Topic 832) (“ASU 2025-10”). ASU 2025-10 provides guidance on the accounting for government grants received by a business entity, including grants related to assets and grants related to income. ASU 2025-10 is effective for annual reporting periods beginning after December 15, 2028, and interim periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period. Adoption of this ASU should be applied using the following transition methods: (i) a modified prospective approach for government grants that are entered into on or after, or not complete as of, the effective date; (ii) a modified retrospective approach for government grants that are entered into on or after, or not complete as of, the beginning of earliest period presented; or (iii) a retrospective approach for all government grants. We are currently evaluating the impact of this new standard on our financial statements and disclosures.

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2. Business Segments, Product Groups and End Markets

The following table presents revenue, profit or loss and significant segment expenses for oursingle operating segment:

(1) Other segment items include interest income, foreign currency (gain) loss, net and other (income) expense.

The following tables represent other balances included in net income or that are regularly provided to the Chief Operating Decision Maker (CODM):

The following table presents our net sales by product group:

(1) Advanced products include flip chip, memory and wafer-level processing and related test services.

(2) Mainstream products include all other wirebond packaging and related test services.

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Net sales by end market consist of the following:

3. Other Income and Expense

Other income and expense consist of the following:

4. Income Taxes

Income tax expense of $79.9 million for the nine months ended September 30, 2026 reflects income taxes, foreign withholding taxes, minimum taxes and certain tax credits.

We monitor on an ongoing basis our ability to utilize our deferred tax assets and whether there is a need for a related valuation allowance. In evaluating our ability to recover our deferred tax assets in the jurisdictions from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax-planning strategies and recent results of operations.

We maintain a valuation allowance on certain U.S. and foreign deferred tax assets. Such valuation allowances are released as the related tax benefits are realized or when sufficient evidence exists to conclude that it is more likely than not that the deferred tax assets will be realized.

Unrecognized tax benefits represent reserves for potential tax deficiencies or reductions in tax benefits that could result from federal, state or foreign tax audits. Gross unrecognized tax benefits were $29.5 million and $36.1 million as of September 30, 2026 and December 31, 2025, respectively. As of September 30, 2026, $26.9 million of our unrecognized tax benefits would reduce our effective tax rate if recognized. Our unrecognized tax benefits are subject to change for effective settlement of examinations, changes in the recognition threshold of tax positions, the expiration of statutes of limitations and other factors.

We have tax returns that are open to examination in various jurisdictions for tax years 2013-2025. The open years contain matters that could be subject to differing interpretations of applicable tax laws and regulations related to the amount and/or timing of income, deductions and tax credits. There can be no assurance that the outcome of examinations will be favorable. In certain circumstances where we elect to appeal the results of an examination, we may

-12- be required to make tax assessment payments to proceed with the administrative appeal process. Current examinations include 2024 Philippine income tax returns and 2020-2021 California income tax returns.

5. Earnings Per Share

Basic earnings per share (“EPS”) is computed by dividing net income attributable to Amkor common stockholders by the weighted-average number of common shares outstanding during the period. The weighted-average number of common shares outstanding is reduced for treasury stock.

Diluted EPS is computed based on the weighted-average number of common shares outstanding plus the effect of dilutive potential common shares outstanding during the period. Dilutive potential common shares include outstanding stock options, performance-vested restricted stock units (“PSUs”), time-vested restricted stock units (“RSUs”) and shares associated with the conversion of debt instruments.

The following table summarizes the computation of basic and diluted EPS:

The following table summarizes the potential shares of common stock that were excluded from diluted EPS because the effect of including these potential shares was anti-dilutive:

There wereno potentially dilutive common shares issuable pursuant to the $1.15 billion aggregate principal amount of our 0.00% convertible senior notes due 2031 (the “2031 Notes”) for the three and nine months ended September 30, 2026, as the average market price of our common stock did not exceed the applicable conversion price during those periods. Refer to Note 11 for additional information on the 2031 Notes.

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6. Accumulated Other Comprehensive Income (Loss)

Changes in accumulated other comprehensive income (loss), net of tax, consist of the following:

(1) Amounts reclassified out of accumulated other comprehensive income (loss) are included as other (income) expense, net (Note 3).

(2) Amounts reclassified out of accumulated other comprehensive income (loss) are included as a component of net periodic pension cost (Note 12) or other (income) expense, net (Note 3).

(3) Foreign currency translation includes the gain (loss) from net investment hedges (Note 13).

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7. Investments

All of our available-for-sale debt investments as of September 30, 2026 are available to fund current operations and are recorded at fair value (Note 14).

The following table summarizes our cash equivalents and available-for-sale debt investments:

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(1)All unrealized losses have been in a continuous loss position for less than 12 months. We do not intend to sell the investments in an unrealized loss position, and we do not believe it is more likely than not that we will be required to sell these investments before recovery of their amortized cost bases.

(2)For the nine months ended September 30, 2026 and 2025, we sold cash equivalent investments for proceeds of $21.8 million and $20.4 million, respectively, and realized no gain or loss on such sales.

The following table summarizes the contractual maturities of our cash equivalents and available-for-sale debt investments as of September 30, 2026:

Actual maturities can differ from contractual maturities due to various factors including whether the issuers have the right to call or prepay obligations without call or prepayment penalties, and we view our available-for-sale debt investments as available for current operations.

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As of September 30, 2026, the amortized cost and the fair market value of our held-to-maturity government bonds (Level 1) maturing within a year were $4.0 million. As of December 31, 2025, the amortized cost and the fair market value of our held-to-maturity government bonds (Level 1) maturing within a year were $3.9 million.

8. Factoring of Accounts Receivable

For certain accounts receivable, we use non-recourse factoring arrangements with third-party financial institutions to manage our working capital and cash flows. Under these arrangements, we sell receivables to a financial institution for cash at a discount to the face amount. As part of the factoring arrangements, we perform certain collection and administrative functions for the receivables sold. For the nine months ended September 30, 2026, we sold receivables totaling $30.4 million, net of discounts and fees, which were insignificant for the respective periods. For the three and nine months ended September 30, 2025, we sold receivables totaling $63.2 million and $88.7 million, respectively, net of discounts and fees, which were insignificant for the respective periods.

9. Property, Plant and Equipment

Property, plant and equipment consist of the following:

As of September 30, 2026, we incurred costs of $553.3 million, including capitalized interest of $8.5 million, related to construction of the Arizona Facility.

In May 2026, we entered into an agreement to purchase approximately 67 additional acres of land for the Arizona Facility for approximately $33 million. The transaction is expected to close in the fourth quarter of 2026.

The following table summarizes our depreciation expense:

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10. Accrued Expenses

Accrued expenses consist of the following:

11. Debt

Short-term borrowings and long-term debt consist of the following:

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(1)In May 2026, we issued the 2031 Notes, which included the exercise in full of the option granted to the initial purchasers to purchase up to an additional $150 million aggregate principal amount of the 2031 Notes. The 2031 Notes are senior, unsecured obligations guaranteed by our wholly-owned subsidiary Guardian Assets, Inc. (“Guardian”). The 2031 Notes will mature on July 15, 2031, unless earlier repurchased, redeemed or converted. We incurred $21.0 million of debt issuance costs associated with the 2031 Notes. As of September 30, 2026, the effective interest rate for the 2031 Notes was 0.35%, primarily reflecting the accretion of debt issuance costs. The net proceeds from the offering of the 2031 Notes were used to fund the cost of entering into privately negotiated capped call transactions (the “Capped Calls”) and for general corporate purposes, including capital expenditures.

Holders may convert their notes at their option under the following conditions: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2026 and only during such fiscal quarter, if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter exceeds (x) before July 15, 2030,150% and (y) on or after July 15, 2030,130%, in each case, of the conversion price on each applicable trading day; (2) during thefive consecutive business days immediately after anyten consecutive trading day period in which the trading price per $1,000 principal amount of notes for each trading day of such five consecutive trading day period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate on each such trading day; (3) if we call any notes for redemption; or (4) upon the occurrence of specified corporate events. On or after April 15, 2031, until the close of business on the second scheduled trading day immediately preceding the maturity date, holders of the 2031 Notes may convert all or any portion of their notes at any time, in integral multiples of $1,000 principal amount, at the option of the holder regardless of the foregoing conditions. Upon conversion, we will settle conversions of the 2031 Notes by paying cash up to the aggregate principal amount of the 2031 Notes and pay or deliver, as applicable, cash or shares of our common stock, based on the applicable conversion rate(s).

As of September 30, 2026, none of the conditions permitting the holders of the 2031 Notes to convert their notes early had been met. Therefore, the 2031 Notes are classified as long-term debt.

We may not redeem the 2031 Notes prior to May 15, 2029. On or after May 15, 2029, we may redeem all or a portion of the 2031 Notes for cash at our option if certain stock price and other conditions are satisfied, at a redemption price equal to 100% of the principal amount to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If we redeem less than all of the outstanding 2031 Notes, at least $150 million aggregate principal amount of notes must be outstanding and not subject to redemption as of, and after giving effect to, delivery of the relevant notice of redemption. No sinking fund is provided for the 2031 Notes.

The initial conversion rate for the 2031 Notes is 9.4013 shares of common stock per $1,000 principal amount of the 2031 Notes, which represents an initial conversion price of approximately $106.37 per share of our common stock. The conversion rate and conversion price are subject to customary adjustments upon the occurrence of certain events. In addition, holders who convert their 2031 Notes in connection with a “make-whole fundamental change” (as defined in the indenture for the 2031 Notes) or a notice of redemption may be entitled to an increase in the conversion rate.

If a “fundamental change” (as defined in the indenture for the 2031 Notes) occurs, then, subject to certain conditions, noteholders may require us to repurchase their 2031 Notes for cash at a price equal to the principal amount of the 2031 Notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the applicable repurchase date.

The 2031 Notes include customary covenants and certain events of default after which the 2031 Notes may be declared immediately due and payable and set forth certain types of bankruptcy or insolvency events of default after which the notes become automatically due and payable.

In connection with the issuance of the 2031 Notes, we entered into the Capped Calls with certain financial institutions at an aggregate cost of approximately $56.4 million. The Capped Calls initially cover, subject to anti-dilution adjustments, approximately 10.8 million shares of common stock underlying the 2031 Notes. The

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Capped Calls can be settled in cash or shares at our option and are expected generally to reduce the potential dilution to common stock upon any conversion of the 2031 Notes and/or offset any cash payments we are required to make in excess of the principal amount of the 2031 Notes. The Capped Calls have an initial strike price of approximately $106.37 per share and an initial cap price of $139.50 per share, which are subject to certain adjustments under the terms of the Capped Calls. The Capped Calls meet the criteria for classification in equity, are not remeasured each reporting period and are included, net of tax, as a reduction to additional paid-in-capital within shareholders’ equity in the Consolidated Balance Sheets.

(2)In May 2025, we entered into a $1.0 billion senior secured revolving credit facility (the “2025 Revolving Credit Facility”) guaranteed by Amkor Technology Singapore Holding Pte. Ltd. (“ATSH”) and Guardian. The maximum borrowing capacity under the 2025 Revolving Credit Facility is $1.0 billion. The 2025 Revolving Credit Facility includes an uncommitted optional accordion of up to $200.0 million, which may be incurred in the form of revolving commitment increases or term loans. As of September 30, 2026, $1.0 billion was available for future borrowings under the 2025 Revolving Credit Facility.

(3)In May 2024, we entered into a ₩80.0 billion (approximately $59 million) term loan agreement with the option to borrow and re-borrow the funds up tosix times per year through May 2027. Principal is payable at maturity, and interest is payable monthly at a fixed rate of 3.95%. As of September 30, 2026, ₩80.0 billion, or approximately $59 million, was available to be drawn.

(4)We entered into various short-term term loans which mature semiannually. Principal and interest are payable in monthly installments. As of September 30, 2026, $3.2 million was available to be drawn.

Certain of our debt is collateralized by the land, buildings, equipment and capital stock of subsidiaries. As of September 30, 2026, the collateralized debt balance was $845.8 million, of which $600.2 million of assets and subsidiary capital stock were pledged as collateral.

The debt of Amkor Technology, Inc. is structurally subordinated in right of payment to all existing and future debt and other liabilities of our subsidiaries. From time to time, Amkor Technology, Inc., ATSH and Guardian guarantee certain indebtedness. The agreements governing our indebtedness contain affirmative and negative covenants, including, among others, covenants to maintain a minimum interest coverage ratio and a maximum consolidated leverage ratio, which restrict our ability to pay dividends and could restrict our operations. These restrictions do not currently have a material impact on our ability to make dividend payments or stock repurchases.

We were in compliance with all debt covenants at September 30, 2026.

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12. Pension Plans

Foreign Defined Benefit Pension Plans

Our subsidiaries in Japan, Korea, Malaysia, the Philippines and Taiwan sponsor defined benefit pension plans. Charges to expense are based upon actuarial analyses. The components of net periodic pension cost for these defined benefit pension plans are as follows:

The components of net periodic pension cost other than the service cost component are included in other (income) expense, net in our Consolidated Statements of Income.

Defined Contribution Pension Plans

We sponsor defined contribution pension plans in Korea, Malaysia, Taiwan and the U.S. The following table summarizes our defined contribution expense:

13. Derivatives

We use foreign currency forward contracts to mitigate foreign currency risk of certain monetary assets and liabilities denominated in foreign currencies. We do not enter into such contracts for trading or speculative purposes. These derivative instruments are not designated as hedging instruments.

We hedge certain net investment positions in foreign subsidiaries. To accomplish this, we enter into foreign currency forward contracts, generally settled monthly, that are designated as hedges of net investments.

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As of September 30, 2026 and December 31, 2025, our foreign exchange forward contracts consisted of the following:

For the three and nine months ended September 30, 2026, we incurred a net gain of $1.2 million and a net loss of $4.7 million, respectively, due to the impact of derivatives not designated as hedging instruments, which includes the forward costs, and the revaluation of the related hedged items. For the three and nine months ended September 30, 2025, we incurred a net loss of $3.8 million and $10.3 million, respectively, due to the impact of derivatives not designated as hedging instruments, which includes the forward costs, and the revaluation of the related hedged items.

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The following table presents the gain or loss recognized on our derivatives designated as net investment hedging instruments:

14. Fair Value Measurements

The accounting framework for determining fair value includes a hierarchy for ranking the quality and reliability of the information used to measure fair value, which enables the reader of the financial statements to assess the inputs used to develop those measurements. The fair value hierarchy consists of three tiers as follows: Level 1, defined as quoted market prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, model-based valuation techniques for which all significant assumptions are observable in the market or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and Level 3, defined as unobservable inputs that are not corroborated by market data. For our Level 2 short-term investments, we consider factors such as actual trade data, benchmark yields, broker/dealer quotes, and other similar data obtained from quoted market prices and independent pricing vendors to determine the fair value of these assets and liabilities.

The fair values of cash, accounts receivable, trade accounts payable, capital expenditures payable and certain other current assets and accrued expenses approximate carrying values because of their short-term nature. The carrying value of certain other non-current assets and liabilities approximates fair value. Our assets and liabilities recorded at fair value on a recurring basis include restricted cash money market funds and short-term investments, including investments classified as cash equivalents. Cash equivalent money market funds and restricted cash money market funds are invested in U.S. money market funds and various U.S. and foreign bank operating and time deposit accounts, which are due on demand or carry a maturity date of less than three months when purchased. No restrictions have been imposed on us regarding withdrawal of balances with respect to our cash equivalents as a result of liquidity or other credit market issues affecting the money market funds we invest in or the counterparty financial institutions holding our deposits.

Our derivative financial instruments are valued using quoted market prices for similar assets. Counterparties to these derivative contracts are highly rated financial institutions.

We also measure certain assets and liabilities, including property, plant and equipment and goodwill, at fair value on a nonrecurring basis.

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We measure the fair value of our debt for disclosure purposes. The following table presents the fair value of our debt:

The estimated fair value of our senior notes and convertible senior notes is based primarily on quoted market prices reported on or near the respective balance sheet dates. The estimated fair value of our revolving credit facilities and term loans is calculated using a discounted cash flow analysis, which utilizes market-based assumptions, including forward interest rates adjusted for credit risk.

15. Commitments and Contingencies

We generally warrant that our services will be performed in a professional and workmanlike manner and in compliance with our customers’ specifications. We accrue costs for known warranty issues. Historically, our warranty costs have been immaterial.

Legal Proceedings

We are involved in claims and legal proceedings and may become involved in other legal matters arising in the ordinary course of our business. We evaluate these claims and legal matters on a case-by-case basis to make a determination as to the impact, if any, on our business, liquidity, results of operations, financial condition or cash flows. Although the outcome of these matters is uncertain, we believe that the ultimate outcome of these claims and proceedings, individually and in the aggregate, will not have a material adverse impact on our business, liquidity, results of operations, financial condition or cash flows. Our evaluation of the potential impact of these claims and legal proceedings could change in the future.

In accordance with the accounting guidance for loss contingencies, including legal proceedings, lawsuits, pending claims and other legal matters, we accrue for a loss contingency when we conclude that the likelihood of a loss is probable and the amount of the loss can be reasonably estimated. We adjust our accruals from time to time as we receive additional information, but the loss we incur may be significantly greater than or less than the amount we have accrued. We disclose loss contingencies if we believe they are material and there is at least a reasonable possibility that a loss has been incurred. Attorney fees related to legal matters are expensed as incurred.

Commitments

We enter into various contracts related to the construction and development of our manufacturing facilities. As of September 30, 2026, the remaining commitments under these contracts were approximately $1,951 million.

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